Fuel injectors for a high-pressure and a low-pressure fuel direct injection device are basically known in the related art. In particular, fuel injectors are also known, with which the dosing of the fuel quantity to be injected into the combustion chambers of the internal combustion engine can be carried out for as long as the valve is open, but also by varying the stroke of the nozzle needle of the fuel injector. The fuel injectors are typically designed as solenoid valves or piezo valves.
Fuel injectors meter the fuel mass required for clean, efficient combustion in the engine and which is to be injected into the cylinder. The control of the fuel injectors typically takes place via a powerstage, the injection preferably being triggered via a low-side switch of the output stage.
The output stage is monitored during operation, so that short-circuits to battery voltage and to the ground of the output stage are detected, and so they can be responded to.
It is further known to also monitor software and hardware faults, e.g., in an electronic control unit.
Publication DE 103 05 178 A1 makes known a method for operating a fuel injector of an internal combustion engine, with which dirty fuel injectors are detected by monitoring the internal combustion engine for proper functioning, and with which suitable cleaning measures are implemented. To monitor proper functioning, the pressure in a fuel accumulator is monitored, and the cylinders are monitored for misfirings. The torque behavior is also monitored and, by specifically enriching and simultaneously monitoring the lambda value, a check is carried out to determine whether the fuel injectors are functioning properly. If contamination is detected, measures are implemented to clean the fuel injector.